1. Field of the Invention
The present invention generally relates to amplifier circuits, and more particularly to an amplifier circuit which includes two operational amplifiers and in which a distortion factor thereof is relatively small.
2. Prior Art
Conventionally, the current at the output stage of the general purpose operational amplifier is set so that the output stage operates in class-B mode, resulting that the crossover distortion must be inevitably generated.
It is impossible to perfectly remove the above crossover distortion by employing the NFB (negative feedback). Hence, the general purpose operational amplifier can not be applied to an audio circuit which requires low-distortion characteristics. The operational amplifiers for specific use of the audio circuits have been produced and sold, however, the price thereof is not extremely high.